Preamble, NOT a part of the Constitution

Jurisprudence educates that a preamble is not an essential part of an act as it is an introductory or preparatory clause that explains the reasons for the enactment, usually introduced by the word "whereas." (G.R. No. 206666; January 21, 2015)
Besides, a preamble is really not an integral part of a law. It is merely an introduction to show its intent or purposes. It cannot be the origin of rights and obligations. Where the meaning of a statute is clear and unambiguous, the preamble can neither expand nor restrict its operation, much less prevail over its text. In this case, it cannot be the authoritative source to show compliance with the Constitution. (G.R. No. 132601; January 19, 1999)